Manually operated small inexpensive pumps are used in dispensing various types of liquids such as detergents and the like. One well known type of pump employs a vertical hollow chamber with a piston vertically slidable therein between bottom and top positions. A trigger pivotally disposed in the pump is used to place the piston in either the normal bottom position or a temporary raised top position. A coil spring disposed in the chamber biases the piston in the bottom position. Pump action can only take place when the piston is in the top position and the liquid being pumped flows through the piston and spring. In order to avoid contamination of the liquid and corrosion of the spring, the spring must be formed from material which does not react chemically with the liquid. Typically the spring material is stainless steel. Consequently, the spring is relatively expensive.
The present invention is directed toward a new arrangement of spring and trigger which enables the biasing action to take place outside of the path of liquid flow whereby the expensive stainless steel coil spring is replaced by an inexpensive spring member of different geometry.